Even before he submitted his design for Ground Zero, Daniel Libeskind was uniquely prepared for the necessity of selling oneself and one’s art to American politicians and finicky citizens. It was less than three years ago that Libeskind beat out four other architects to become the winning designer of a $62.5 million addition to the Denver Art Museum. And while the media scrutiny and public interest in Denver was a fraction of that with which Libeskind would contend in New York, the architect’s skill at presenting his work as a public boon was evident in the Denver competition.